"I want to learn from players like Lionel Messi and Xavi Hernández—and I want to help the club win more titles," said Sánchez. Sánchez's debut season for Barcelona was mired with short-term injuries. He made his debut on 14 August 2011 against archrivals Real Madrid in the 2011 Supercopa de España first leg away match, suffering a thigh injury after a challenge by Marcelo. Barcelona won the tie 5–4 on aggregate. He made his return two weeks later as a substitute in the 2011 UEFA Super Cup, won by Barca 2–0. Sánchez then started the opening match of La Liga, at home against Villarreal, and scored his first goal in a 5–0 win. A week later, on 10 September, he was stretchered off after 30 minutes following a challenge from Dani Estrada in a domestic league match against Real Sociedad. Sánchez returned on 1 November in an away match against Viktoria Plzeň. On 10 December, he scored Barça's equaliser against Real Madrid in a match they went on to win 3–1 away at the Santiago Bernabéu Stadium. On 14 February 2012, Sánchez scored the first and second UEFA Champions League goals of his career in Barcelona's 3–1 victory against Bayer Leverkusen. In the 2012–13 campaign, on 2 October 2012 Sánchez scored the first goal for Barcelona in a 2–0 away win against Benfica. On 10 February 2013, then scored his first goal of the Liga season in Barça's 6–1 home win against Getafe. From February onwards, Sánchez scored in matches against Deportivo de La Coruña, Mallorca, Athletic Bilbao, Real Betis, Atlético Madrid and Espanyol to end the season with eight league goals. Barcelona won the league title, ending the season with 100 points. On 26 October 2013, Sánchez scored the winning goal as Barça beat Real Madrid 2–1 at Camp Nou in the first Clásico fixture of the 2013–14 La Liga season. On 5 January 2014, Sánchez scored his first hat-trick for Barcelona in a 4–0 win against Elche. He ended the 2013–14 season with a career-high 21 goals in all competitions, including 19 in La Liga. Arsenal On 10 July 2014, Sánchez signed for Arsenal on a long-term contract for a transfer fee of £31.7 million. Sánchez was given the squad number 17, previously worn by Nacho Monreal, who took the vacant number 18 instead. In a statement released by the club, Sánchez said that he was "so happy